The steering wheel of a vehicle includes an air bag and an inflator which is capable of causing it to expand. A cable reel is used to connect the inflator to the vehicle's electrical circuits.
Referring to FIGS. 7 to 9, movable body 5 is rotatably mounted on fixed body 2 with a cylindrical space therebetween. Cable reel 1, including coiled flat cable 6, is in the space between fixed body 2 and movable body 5. The cylindrical space between the movable body and the fixed body has a sufficient radius so that flat cable 6 can coil and uncoil in response to rotation of movable body 5. The fixed body is mounted on combination switch body 3 which, in turn, is on steering column 4 adjacent steering wheel 10 and movable body 5 rotates with steering wheel 10.
Combination switch body 3 carries turn indicator member 7 on one side and light switch member 8 on the other. They are actuated by operating lever 7b extending from switch box 7a and operating lever 8b extending from switch box 8a, respectively.
The foregoing device is assembled by fixing movable body 5, carrying cable reel 1 to the steering column 4 beneath steering wheel 10. Fixed body 2, with rotatably mounted movable body 5, is attached to the upper surface of switch body 3 and below steering wheel 10. When the device of the foregoing type is assembled, cable reel 1 is interposed between steering wheel 10 and the upper surface of switch body 3 which, in turn, is fixed to steering column 4. operating levers 7b and 8b extend from either side out of switch boxes 7a and 8a.
When cable reel 1 is between steering wheel 10 and switch body 3, from which operating levers 7b and 7a project, the height H is quite large and thus, the operating levers are separated from steering wheel 10 by a substantial distance S. This is of particular importance because recent innovations require more circuits to be carried by flat cable 6. As a result, cable reel 1 has increased to about 1.5 to 2 times the prior height. When distance S between steering wheel 10 and operating levers 7b and 8b is increased in accordance with the foregoing, the driver can no longer actuate the operating levers without releasing the steering wheel. For safety reasons, this is undesirable.
In an effort to solve the foregoing problem, it has been suggested that operating levers 7b and 8b be bent as shown in broken lines in FIG. 7 and in full lines in FIG. 10. This brings the ends closer to steering wheel 4, thereby reducing distance S. However, this solution has the drawback of requiring a special bent shape for the operating levers which involves increased costs. In addition, the bent levers create problems for the circuits contained therein.
An additional mechanism is used to automatically return the turn indicator lever and switch to their neutral position. Since cancel cam 9 is the element which effectuates this as steering wheel 10 is rotated, the former must be disposed at the attachment position of operating lever 7b. As a result, it is an increased distance from steering wheel 10. Therefore, the various elements comprising cancel cam 9 must be installed separately from the remainder of the device. The number of parts and the number of steps required for assembly are both increased.
Another solution is based upon Japanese OPI 9-129092. As shown in FIG. 11, fixed body 2' is formed directly from combination switch body 3'. Movable body 5' rotates relative to switch body 3' and forms a ring-shaped space with switch body 3'. Flat cable 6' is located therein.
The foregoing is an improvement on the other prior art mentioned, and allows operating levers 7b and 8b to be closer to steering wheel 10. However, since switch body 3' doubles as the fixed body for the cable reel, and the cable reel and combination switch are formed integrally, a problem arises. Specifically, should one of the bodies be damaged (e.g. cracked, chipped, or deformed) both the cable reel and the combination switch must be replaced.
In addition, cancel cam 9' is disposed below fixed body 2'. This requires that the cam parts be installed separately from one another. Moreover, the operating lever for the turn indicator switch is substantially below steering wheel 10. This is particularly true if flat cable 6 is of increased height as is the current trend. Thus, the operating lever will still be farther away from steering wheel 10 than is optimally desirable.